Gerotor fluid controller with twistable blade energy storing means

ABSTRACT

An improved fluid controller includes a gerotor gear assembly having an internally toothed stator and an externally toothed rotor which are operable to provide a metered flow of fluid. A valve sleeve is movable axially between a closed position blocking fluid flow to and from the gerotor gear assembly and an open position in which fluid is ported to the gerotor gear assembly. Upon initial rotation of an input member, the valve sleeve is moved axially from the closed position to the open position. During axial movement of the valve sleeve, the input member resiliently twists a plurality of torsion blades which extend between the input member and a wobble shaft connected with the rotor of the gerotor gear assembly. When the rotation of the input member is stopped, the resiliently twisted torsion blades are effective to rotate the valve sleeve relative to the input member to effect movement of the valve sleeve to its closed position. The torsion blades are connected with the input shaft and wobble shaft in such a manner as to prevent the inducing of stresses at the connections between the blades and the two shafts. In addition, the torsion blades cooperate with the two shafts in such a manner as to minimize lost motion at the connections between the blades and the shafts. The blades have major sides with relatively large surface areas to facilitate the dissipating of heat resulting from flexing of the blades.

United States Patent [191 Miller Nov. 11, 1975 1 1 GEROTOR FLUID CONTROLLER WITH TWISTABLE BLADE ENERGY STORING MEANS [75] Inventor: Laurence L. Miller, West Lafayette,

] Assignee: TRW Inc., Cleveland, Ohio Filed: Feb. 19, 1974 Appl. No.: 443,463

[56] References Cited UNITED STATES PATENTS 6/1941 Fulcher 64/15 B 1/1968 Lech et al. 180/792 R 5/1968 Pruvot et al 418/61 B 8/1971 Venable et a1. 418/61 B Primary Examiner-John J. Vrablik [57] ABSTRACT An improved fluid controller includes a gerotor gear assembly having an internally toothed stator and an externally toothed rotor which are operable to provide a metered flow of fluid. A valve sleeve is movable axially between a closed position blocking fluid flow to and from the gerotor gear assembly and an open position in which fluid is ported to the gerotor gear assembly. Upon initial rotation of an input member, the valve sleeve is moved axially from the closed position to the open position. During axial movement of the valve sleeve, the input member resiliently twists a plurality of torsion blades which extend between the input member and a wobble shaft connected with the rotor of the gerotor gear assembly. When the rotation of the input member is stopped, the resiliently twisted torsion blades are effective to rotate the valve sleeve relative to the input member to effect movement of the valve sleeve to its closed position. The torsion blades are connected with the input shaft and wobble shaft in such a manner as to prevent the inducing of stresses at the connections between the blades and the two shafts. In addition, the torsion blades cooperate with the two shafts in such a manner as to minimize lost motion at the connections between the blades and the shafts. The blades have major sides with relatively large surface areas to facilitate the dissipating of heat resulting from flexing of the blades.

10 Claims, 9 Drawing Figures 32 or 100 /28 //0 4 62 74 L36 I24 I20 I A J 56 [I I US. Patent Nov. 11, 1975 Sheet 1 012 US. Patent Nov. 11,1975 Sheet2of2 3,918,856

FIG. 3

i M i 1 g //////////7//// GEROTOR FLUID CONTROLLER WITH TWISTABLE BLADE ENERGY STORINGMEANS BACKGROUND OF THE INVENTION This invention relates generally to an improved fluid controller and more specifically to a fluid controller which has a rotary input memberassociated with a valve member to effect movement of the valve member upon rotation of the input member relative thereto. Steering controllers of the type to which this invention relates are used to effect powered hydrostatic steering of a vehicle.

Fluid controllers for use in hydrostatic steering of a vehicle are known. Such controllers include a gerotor mechanism for metering fluid flow to a power steering cylinder and a valve mechanism for porting fluid to the gerotor mechanism and to the steering-cylinder. An operator-controlled input shaft is connected with the valve member to effect movement of the valve member upon rotation of the input member relative thereto. Upon initial rotation of the input shaft and movement of the valve member from an initial position a torsion coupling stores energy to return the valve member to its initial position. The torsion coupling is connected between the gerotor mechanism and the input shaft. This known torsion coupling includes a torsion rod which has a relatively long axial length and is twisted about its central axis upon movement of the valve member. Due to the fact that the torsion rod is sized so as to have a desired spring rate, it has a limited outer surface area for-dissipating heat which results during flexing of the rod. In addition, the torsion rod and its connections with the input shaft and valve member are relatively expensive to fabricate. Two known fluid controllers having torsion coupling arrangements are disclosed in US. Pat. Nos. 3,443,378 and 3,452,543.

SUMMARY OF THE PRESENT INVENTION The present invention provides an improved fluid controller having at least one torsion blade which is resiliently twisted about its central axis upon rotation of an input member relative to a valve member. In one specific preferred embodiment of the invention, a pair of torsion blades are utilized to minimize the width and axial extent of the blades and provide a desired spring rate. The opposite end portions of the torsion blades are disposed in mounting slots formed in the input member and in a member connected with the gerotor mechanism.

To minimize lost motion upon initial rotation of the input member, the torsion blades are advantageously bowed or curved so that they press firmly against the sides of the mounting slots. In order to prevent the induction of relatively high levels of stress in the torsion blades adjacent to the outer edges or corners of the mounting slots, the blades are formed with protuberances which prevent engagement of the blades with the corners of the slots as the blades are twisted.

Accordingly, the new and improved fluid controller of the present invention has a simple torsion coupling which is inexpensive to fabricate, is relatively free of stress concentrations, and has a minimum of lost motion. These advantages are provided by the torsion blade construction which is resiliently twisted about its central axis upon movement of an input member relative to the valve member. The valve member is movable from an initial position to port fluid to the gerotor gear assembly and the resiliently deflectable'torsion blade construction is twisted about its central axis by the input force applied to the input shaft and thereby stores energy to effect movement of the valve member back to its initial position when the input force is removed.

BRIEF DESCRIPTION or THE DRAWINGS The foregoing and other objects and features of the present invention will become more apparent upon a consideration of the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is an axial sectional view of a fluid controller constructed in accordance with the present invention;

FIG. 2 is a fragmentary view, taken generally along the line 2-2 of FIG. I; A

FIG. 3 is an enlarged plan view of thetorsion blades;

FIG. 4 is a view taken along the line 44 of FIG. 3, further illustrating the curved construction of the torsion blades;

FIG. 5 is an enlarged sectional view, taken generally along the line 55 of FIG. 3 and illustrating the relationship between inner end portions of the torsion blades;

FIG. 6 is an enlarged section view, taken generally along the line 6-6 of FIG. 3, illustrating the relationship between outer end portions of the torsion blades;

FIG. 7 is an enlarged sectional view, taken generally along the line 7-7 of FIG. 3, further illustrating the relationship between the inner end portions of the torsion blades when they are in an unrestrained condition;

FIG. 8 is a sectional view of a portion of the controller shown in FIG. 1 and taken along the line 8-8 thereof,

FIG. 9 is a schematic view of a portion of the fluid controller illustrating the gear assembly therein.

DESCRIPTION OF ONE PREFERRED EMBODIMENT OF THE INVENTION A fluid controller 10 constructed iniaccordance with the present invention is illustrated in FIG. 1 and includes a gerotor gear assembly 12. The gerotor gear assembly 12 is operable to provide a metered flow of fluid upon actuation of a control valve 14 in response to rotation of an input shaft 16. The fluid controller 10 has an improved torsion coupling assembly l8 which is effective to return the valve 14 back to its initial or unactuated condition, as will be described below.

The fluid controller 10 includes a generally cylindrical casing or housing 22 which is connected 'with a pump or other source of fluid (not shown) by a conduit 24. The housing 22 is connected to a reservoir or drain through a second conduit 28. Upon initial rotation of the input shaft 16, a ball 34 cooperates with a generally helical groove 36 to axially shift a valve sleeve 32. This axial shifting of the valve sleeve 32 enables high pressure fluid to flow from an annular pressure groove to the gerotor gear assembly 12. Depending upon whether the input shaft 16 is rotated in a clockwise or counterclockwise direction with a resulting left or right shifting of the valve sleeve 32, a measured fluid output from the gerotor gear assembly 12 is ported by the valve to either a conduit 44 connected with one end of a piston and cylinder type hydraulic motor (not shown) or to a conduit 46 connected with the opposite end of the motor.

When the input shaft 16 is rotated in a clockwise direction. the ball 34 and helical groove 36 cooperate to shift the valve sleeve 32 toward the left. This ports hydraulic fluid to the gerotor motor assembly 12 and from the gerotor gear assembly 12 to the conduit 46. Upon counterclockwise rotation of the input shaft 16, the valve sleeve 32 is shifted toward the right. This ports hydraulic fluid from a second pressure groove 48 to the gerotor gear assembly 12 and from the gerotor gear assembly 12 to the conduit 44. The specific details of the porting arrangement may vary and are generally known and specifically may be as illustrated in U.S. Pat. No. 3,452,543. Therefore, these details will not be described herein.

The gerotor gear assembly 12 includes an internally toothed stator 50 which circumscribes an externally toothed rotor 54. The rotor 54 has one less tooth than the stator 50 and cooperates with the stator, a spacer plate 56, and a bearing plate 58 to form a plurality of fluid receiving pockets which provide a metered fluid output upon rotational and orbital movement of the rotor relative to the stator. A commutator valve 62 cooperates with the gerotor gear assembly 12 to port fluid to and from the pockets formed between the stator 50 and rotor 54. The construction of the gerotor gear assembly 12 and the manner in which it cooperates with the valve assembly 14 and commutator valve 62 is the same as is disclosed in U.S. Pat. No. 3,452,543 which is incorporated herein in its entirety by this reference thereto. In order to avoid prolixity of description, the known relationships between these components will not be further described herein.

In accordance with the present invention, the torsion coupling 18 includes a pair of torsion blades 66 and 68 (see FIGS. 1-4). The torsion blades 66 and 68 extend between the input shaft 16 and a wobble shaft 74 having an externally toothed head portion 76 disposed in meshing engagement with internal teeth on the rotor 50. Upon rotation of the input shaft 16, the torsion blades 66 and 68 are resiliently twisted as the valve sleeve 32 is shifted axially to an actuated position. Twisting of the torsion blades 66 and 68 stores potential energy to effect a shifting of the valve sleeve 32 back to its initial or closed position upon interruption of rotation of the input member 16.

Upon clockwise rotation of the input member 16 with the valve sleeve 32 in the closed position of FIG. I, the torsion blades 66 and 68 are resiliently twisted in a clockwise direction about their longitudinal axes. As the torsion blades 66 and 68 are twisted, the valve sleeve 32 is shifted toward the left by the interaction between the ball 34 and helical groove 36. Once the valve sleeve 32 has been moved to an actuated position, a stop element (not shown) on the input shaft 16 rotates the valve sleeve 32 with the input shaft. When the input force on the input shaft 16 is interrupted, the potential energy stored in the resiliently twisted torsion blades 66 and 68 is sufficient to cause the valve sleeve 32 to rotate in a counterclockwise direction and to be shifted axially toward the right to the position of FIG. 1 by the interaction between the ball 34 and helical groove 36. This return of the valve sleeve is effected by the torsion blades turning the shaft 16 relative to the valve sleeve 32.

Similarly, if the input shaft 16 is rotated in a counterclockwise direction, the torsion blades 66 and 68 are resiliently twisted in a counterclockwise direction during initial rotation of the input shaft 16. As the torsion blades are twisted the valve sleeve 32 is shifted toward the right from the position of FIG. 1 to port fluid to the gerotor gear assembly 12 and to the steering cylinder. Upon interruption of the input force on the input shaft 16, the potential energy stored in the resiliently twisted torsion blades 66 and 68 is effective to cause the valve sleeve 32 to rotate and be shifted toward the left under the influence of the ball 34 and helical groove 36.

The blade 68 has a pair of relatively large major sides 82 and 84 (see FIGS. 3 and 4) which are exposed to hydraulic fluid within a valve chamber 88 (FIG 1). As the hydraulic fluid flows through the valve chamber 88, it passes along the major side surfaces 82 and 84 of the blade 68. Such flow cools the blade and dissipates heat generated due to twisting thereof. In addition to the major sides 82 and 84, the blade 68 has a pair of minor sides 92 and 94 which extend parallel to each other in such a manner that the blade 68 has a generally rectangular cross sectional configuration. Although the configuration of only the blade 68 is shown in FIG. 3, it should be understood that the blade 66 has the same configuration as the blade 68.

The blades 66 and 68 are connected with the input shaft 16 and wobble shaft 74 by tongue and groove type connections 98 and 100 (see FIGS. 1 and 2) which are relatively simple and inexpensive to manufacture. Thus, the connection 98 with the input shaft 16 is formed by a slot 104 which extends diametrically across the inner end of the shaft 16 and is sized to receive the outer end portions 108 and 110 of the torsion blades 66 and 68. To position the torsion blades radially relative to the slot 104, a central locating hole 112 is formed in the end of the input shaft 16 and receives axially projecting tongues 118 and 120 formed on the torsion blades 66 and 68.

A connection 100 with the wobble shaft 74 is of a construction which is generally similar to the connection 98 and includes a slot 122 formed in an externally toothed head end portion 124 of the wobble shaft 74. The slot 122 extends diametrically across the wobble shaft 74 and receives inner end portions 126 and 128 of the torsion blades 66 and 68. The externally toothed head end 124 of the wobble shaft 74 is disposed in meshing engagement with axially extending internal splines or teeth 132 formed on the valve sleeve 32. Therefore during rotation of the input shaft 16, the torsion blades 66 and 68 apply torque to the valve sleeve 32 through the head end portion 124 of the wobble shaft 74. The wobble shaft 74 is drivingly connected to the valve sleeve 32 and this connection is provided by splines 132 on the valve spool which mesh with a cooperating gear on the wobble shaft 74. Since the connection 100 is formed in the head end portion 124 of the wobble shaft 74, the torsion blades 66 and 68 are rotated with the wobble shaft and valve sleeve 32 as the wobble shaft is rotated about its central axis during rotational movement of the rotor 54 relative to the stator 50. ()f course, the rotor 54 and wobble shaft 74 rotate about their central axes in the same direction as the input shaft 16.

During operation of the gerotor gear assembly 12, the rotor 54 is also subjected to orbital movement relative to the stator 50. The direction of orbital movement of the rotor is opposite from the direction in which it rotates about its central axis. The orbital movement of the rotor 50 results in oscillatory movement of the head end 124 of the wobble shaft 74 relative to the valve spool splines 132 and the torsion blades 66 and 68. To facilitate this oscillatory movement of the head end 124 of the wobble shaft 74, the inner end portions 126 and 128 of the blades 66 and 68 are cut away to clear the diametrically extending bottom surface 136 of the slot 124. Thus, the blade 68 has sloping end surfaces 138 and 140 (see FIG. 3) which are spaced from the bottom surface 136 of the slot 124. If the end portion 128 of the blade 68 was cut square, that is if it was cut along a line extending perpendicular to the minor sides 92 and 94 of the blade, the end portion 128 of the blade to be engaged by the bottom 136 of the slot 122 and would interfere with the movement of the wobble shaft 74. Although the configuration of the inner end portion 128 of only the blade 68 has been shown in FIG. 3, it should be understood that the inner end portion 126 of the blade 66 has the same configuration.

When the torsion blades 66 and 68 are twisted, the major sides of the torsion blades are twisted relative to the sides of the slots 104 and 122. If the major sides of the torsion blades 66 and 68 engage the extending corner portions of the slots 104 and 122, severe localized stress conditions would be induced in the torsion blades 66 and 68. Of course, these severe localized stress conditions would be detrimental to the operating life of the torsion blades.

To prevent the engagement of the major sides of the torsion blades 66 and 68 with the corner edge portions of the slots 104 and 122, the blades 66 and 68 are formed with rounded protuberances which hold the blades 66 and 68 away from the corner edge portions of the slots. Thus, the outer end portion 110 of the blade 68 is formed with a pair of protuberances or bumps 144 and 146 (see FIGS. 3 and 6). The protuberances 144 and 146 engage a side surface 150 of the slot 104 (see FIG. 2) at a location axially inwardly from the outer corner edge portion of the slot 104. The arcuate radius of the protuberances 144 and 146 is sufficient to hold the major side 82 of the blade 68 away from the corner edge portion of the slot 104 as the blade 68 is twisted or flexed.

The inner end of the blade 68 is also formed with a pair of protuberances 154 and 156 (see FIG. 3) which engage a side surface 158 (see FIG. 2) of the slot 122 to hold the major side surface 82 of the blade 68 away from the corners of the slot during twisting of the blades 66 and 68. The curved configuration of the protuberances 144, 146, 154, and 156 formed in the blade 68 enable the protuberances 144, 146 to rock and slide freely relative to the input shaft 16 and wobble shaft 64 as the blade is twisted or flexed.

The blade 66 is provided with protuberances similar to the protuberances formed on the blade 68. Thus, the outer end portion 108 of the blade 66 is formed with a pair of protuberances 162 and 164 (FIG. 6) which have the same configuration as the protuberances 144 and 146 formed in the blade 68. Similarly, the inner end portion 126 of the blade 66 is formed of a pair of protuberances 166 and 168 (FIG. 5) which have the same configuration as the protuberances 154 and 156 on the blade 68. Of course, the protuberances 162, 164, 166, and 168 engage side surfaces of the slots 104 and 122 which are opposite from the side surfaces engaged by the protuberances on the blade 68.

The interaction between the axially projecting tongues 118 and 120 on the blades 66 and 68 and the cylindrical hole 112 in the input shaft 16 (see FIG. 2) holds the outer end portions 108 and of the blades against movement radially toward the valve spool 32. The inner end portions 126, 128 of the blades 66, 68 are also held against movement radially toward the valve spool 32. This is accomplished by the splines 132. The inner end portions of the blades 66, 68 are held in a centered relationship with the valve spool 32 by the splines 132 (FIG. 8). Since the end portions 126, 128 of the blades do not rotate relative to the splines 132 on the valve spool, the splines 132 hold the blades 66 and 68 against sidewise movement. Accordingly both ends of the blades are restrained from moving radially, and will not interfere with rotation of the valve sleeve 32.

To hold the inner end portions 126 and 128 of the blades 66 and 68 against axial movement relative to each other, a pair of oppositely projecting dimples are formed on the inner end portions 126 and 128 of each of the blades 66 and 68. Thus, the blade 68 is formed with a dimple 172 which projects outwardly from the major side 82 of the blade. A second dimple 174 projects outwardly from the opposite side 84 of the blade 68. The two dimples 172 and 174 cooperate with a pair of dimples 178 and 180 formed in the blade 66 in the manner illustrated in FIG. 5 to hold the two blades 66 and 68 against endwise or axial movement relative to each other.

In order to minimize lost motion between the torsion blades 66 and 68 and the input shaft 16 and wobble shaft 74 upon initiation of relative rotation between the input and wobble shafts, the torsion blades are designed in such a manner that they press firmly against the side walls of the slots 104 and 122 even though the manufacturing tolerances with which the slots are formed may be such that they are not the exact size desired. To provide for this firm abutting engagement of the torsion blades 66 and 68 with the side walls of the slots 104 and 122, the torsion blades are formed with a longitudinally extending arcuate curvature. Thus, the torsion blade 68 is bowed so that the major side surface 82 has a convex curvature while the major side surface 84 has a concave curvature (see FIG. 4). The torsion blade 66 is formed with the same curved or bowed configuration as the torsion blade 68.

When the two torsion blades 66 and 68 are placed in the fluid controller 10, they are positioned with their concavely bowed or curved major sides in a side-byside or facing relationship as shown in FIG. 4. This results in an angular separation of the blades at their end portions in the manner illustrated in FIGS. 2 and 7. As the blades are inserted into the slots 104 and 122, the various protuberances on the end portions of the blades engage the side surfaces of the slots and press the adjacent major sides together. Thus, the blades in effect act as springs and try to return to their free state. Accordingly, if the slots 104 and 122 have too great a width, due to manufacturing tolerances or other reasons, the oppositely curved or bowed blades acting as springs will resiliently press the protuberances on the end portions of the blades against the sides of the slot. Therefore lost motion between the input shaft 16 and wobble shaft 74 is minimized.

In view of the foregoing description it can be seen that the fluid controller 10 includes a valve assembly 14 which is actuated upon rotation of input shaft 16 to activate a gerotor gear assembly 12. When the input shaft H) is initially rotated in u clockwise direction with the valve assembly 14 in the position of HO. 1, the blades 66, 68 twist. This twisting results because of the resistance of the rotor 54 to rotation. As this occurs, the input shaft 16 rotates relative to the wobble shaft 74. This clockwise rotation of the input shaft 16 relative to the wobble shaft 74 flexes or twists the torsion blades 66 and 68. As the torsion blades 66 and 68 are being twisted or flexed, the ball 34 cooperates with the helical groove 36 to shift the valve sleeve 32 axially toward the left (as viewed in FIG. 1). As the valve sleeve 32 shifts toward the left, the splines 132 on the inside of the valve spool 32 slide relative to the external teeth on the head portion 124 of the wobble shaft 74.

This leftward movement of the valve spool 32 operates the valve assembly 14 from the closed condition to an actuated condition in which fluid under pressure is ported from the pressure supply to the gerotor gear assembly 12. During continued clockwise rotation of the input shaft 16, the rotor 54 is also rotated in a clockwise direction and a metered flow of fluid is returned to the valve and ported to the steering cylinder through conduit 46. It should be noted that the other motor conduit 44 is connected withdrain through the valve assembly 14.

When rotation of the input shaft 16 is stopped with the valve sleeve 32 in the leftward actuated condition, energy is stored in the flexed torsion blades 66 and 68 and the torsion blades 66 and 68 apply a force tending to effect relative rotation between the input shaft 16 and valve spool 32. If such occurs, the valve spool 32 is shifted back toward its initial position by the interaction between the ball 34 and the groove 36. As this occurs, the twisted or flexed torsion blades 66 and 68 relax.

Upon rotation of the input shaft 16 in a counterclockwise direction, the valve spool 32 is shifted toward the right and the rotor 54 is rotated in a counterclockwise direction to provide a metered flow of fluid to the motor conduit 44. As the valve spool 32 is shifted toward the right, the torsion blades 66 and 68 are flexed. During continued counterclockwise rotation of the input member 16 and counterclockwise rotation of the rotor 54 and wobble shaft 74 about their central axes, the torsion blades 66 and 68 are maintained in a flexed or twisted condition. However, upon interruption of counterclockwise rotation of the input shaft 16, the stored energy in the torsion blades acts as described above.

Although the torsion coupling 18 has been formed by a pair of torsion blades 66 and 68 in the illustrated embodiment of the invention, it is contemplated that either a greater or lesser number of torsion blades could be utilized. However, it should be noted that the utilization of a plurality of torsion blades 66 and 68 enables the desired spring rate to be obtained with torsion blades of a relatively short axial length.

Having described one specific preferred embodiment of the invention, the following is claimed:

1. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing having first and second outlet ports, gerotor gear means connected with said housing and operable in one direction to provide a metered flow of fluid to said first outlet port and operable in another direction to provide a metered flow of fluid to said second outlet port, commutator valve means associated with said gerotor gear means for dirccting fluid to and from said gerotor gear means. directional control valve means for porting fluid to said commutator valve means and for porting fluid received from said commutator valve means to one of said outlets, said directional control valve means including a valve member movable in a first direction from an initial position to a first actuated position to port a flow of fluid to said commutator valve means and to port fluid from said commutator valve means to said first outlet and movable in a second direction from the initial position to a second actuated position to port a flow of fluid to said commutator valve means and to port fluit from said commutator valve means to said second outlet, an input member operatively connected with said valve member, said input member being rotatable in a first direction to effect movement of said valve member from said initial position to said first actuated position and being rotatable in a second direction to effect movement of said valve member from said initial position to said second actuating position, resiliently twistable blade means operatively connected with said input member and said directional central valve means for storing energy to effect movement of said valve member from said actuated positions back to said initial position, means for enabling twisting of said blade means about the central axis thereof upon rotation of said input member to store energy to effect subsequent movement of said valve member from one of said actuated positions to said initial position, and said blade means being located in a fluid flow path between said commutator valve means and said directional control valve means.

2. An apparatus as set forth in claim 1 wherein said gerotor gear means includes an internally toothed stator member and an externally toothed rotor member circumscribed by said stator member, said rotor member having one less tooth than said stator member and being rotatable about its own central axis and orbital about the central axis of said stator member during operation of gerotor gear means.

3. An apparatus as set forth in claim 1 wherein said blade means includes a blade member having major sides of a first area and minor sides of a second area which is substantially less than said first area.

4. An apparatus as set forth in claim 1 wherein said blade means includes a pair of blade members each of which has one end portion connected with said input member and another end portion connected with said gerotor gear.

5. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing having first and second outlet ports, gerotor gear means connected with said housing and operable in one direction to provide a metered flow of fluid to said first outlet port and operable in another direction to provide a metered flow of fluid to said second outlet port, commutator valve means associated with said gerotor gear means for directing fluid to and from said gerotor gear means, directional control valve means for porting fluid to said commutator valve means and for porting fluid received from said commutator valve means to one of said outlets, said directional valve means including a valve member movable in a first direction from an initial position to a first actuated position to port a flow of fluid to said commutator valve means and to port fluid from said commutator valve means to said first outlet and movable in a second direction from the initial position to a second actuated position to port a flowv offluid to said commutator valve means and to port fluid from said commutator valve means to said second outlet, an input member operatively connected with said valve member, said input member being rotatable in a first direction to effect movement of said valve member from said initial position to said first actuated position and being rotatable in a second direction to effect movement of said valve member from said initial position to said second actuated position, resiliently twistable blade means operatively connected with said input member and said valve means for storing energy to'effeet movement of said valve member'from said actuated positions back to said initial position, and'means for enabling twisting of said blade means about the 'central axis thereof upon rotation of said input member to store energy to effect subsequent movement of said valve member from one of said actuated positions to said initial position, said gerotor gear means including an internally toothed stator and an externally toothed rotor disposed in meshing engagement with said stator, said rotor having one less tooth than said stator and being rotatable about its own central axis and orbital about the central axis of said stator during operation of said gerotor gear means, a, wobble shaft having a first head end portion connected with said rotor for rotational and orbital movement therewith and a second head end portion connected with said valve member, said blade means having an end portion connected directly to said second head end portion of said wobble shaft.

6. An apparatus as set forth in claim wherein said second head end portion of said wobble shaft includes surface means for defining a slot in the second head end portion of said wobble shaft, said end portion of said blade means being disposed in said slot.

7. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing, gerotor gear means connected with said housing and operable in one direction to provide a metered flow of fluid to a first port and operable in another direction to provide a metered flow of fluid to a second port, valve means for porting fluid to said gerotor gear means, said valve means including a valve member movable in a first direction from an initial position to a first actuated position to port a flow of fluid to said gerotor gear means during operation of said gerotor gear means in the one direction and movable in a second direction from the initial position to a second actuated position to port a flow of fluid to said gerotor gear means during operation of said gerotor gear means in the other direction, an input member connected with said valve member, said input member being rotatable in a first direction in response to one input force to effect movement of said valve member from said initial position to said first actuated position and being rotatable in a second direction in response to another input force to effect movement of said valve member from said initial position to said second actuated position, resiliently twistable blade means connected with said input member and said gerotor gear means for storing energy to effect movement of said valve member from one of said actuated positions to said initial position upon interruption of the input force on the input member and means for effecting twisting said blade means about its central axis upon rotation of said input member to store energy to effect subsequent movement of said valve member from one of said actuated positions to said initial position, said blade means including a pair of blade members each of which has one end portion connected with said input member and another, end portion connected with said gerotor gear means, each of said pair of blade members having a convexly curved major side and a coneavely curved major side, said pair of blade members being disposed in a side-by-side relationship with said coneavely curved major side of one of said blade members facing a curved major-side of the other of said blade members.

8. An apparatus as set forth in claim 7 further including first surface means fixedly connected with said input member for engaging'said convexly curved major sides of each of said blade members and pressing said blade members toward each other to provide a tight connection between said blade members and said input member, and second surface means connected with said valve member for engaging said convexly curved major sides of each of said blade members and pressing said blade members toward each other to provide a tight connection between said blade member and said valve member.

9. An apparatus for use in controlling a flow of fluid,

said apparatus comprising a housing having an inlet port and a pair of outlet ports, metering means located in said housing and operable to provide a metered flow of fluid, said metering means including an internally toothed member and an externally toothed member disposed in meshing engagement and supported for relative orbital and rotational movements, valve means located in said housing and operable from an initial condition to an actuated condition to port fluid to said metering means and to port fluid from said metering means to a selected one of said outlet ports, a shaft having a first head end portion connected with said externally toothed member for movement therewith and a second head end portion connected with said valve means, a rotatable input member, and means for enabling operation of said valve means from the initial condition to an actuated condition in response to rotation of said input member and for storing energy to effect operation of said valve means from an actuated condition to said initial condition, and means including a pair of resiliently twistable blade having a first end portion connected with said input member and a second end portion connected directly to said second head end portion of said shaft and which twists about its longitudinal axis upon rotation of said input member, said pair of resiliently twistable blades being of equal length and wherein said shaft has a slot therein for receiving one end portion of said blades, the other end portion of said blades being located in a slot in said input shaft, said input shaft further having a locating hole for receiving axially projecting tongues formed on said blades, each of said pair of blade members having a convexly curved major side and a coneavely curved major side, said pair of blade members being disposed in a side-by-side relationship with said cancavely curved major side of one of said blade members facing a coneavely curved major side of the other of said blade members.

10. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing having an inlet port and a pair of outlet ports, metering means located in said housing and operable to provide a metered flow of fluid, said metering means including an internally toothed member and an externally toothed member disposed in meshing engagement and supported for relative orbital and rotational movements, valve means located in said housing and operable from an initial condition to an actuated condition to port fluid to said metering means and to port fluid from said metering means to a selected one of said outlet ports, a shaft having a first head end portion connected with said externally toothed member for movement therwith and a second head end portion connected with said valve means, a rotatable input member, and means for enabling operation of said valve means from the initial condition to an actuated condition in response to rotation of said input member and for storing energy to effect operation of said valve means from an actuated condition to said initial condition, said means including a pair of resiliently twistable blade having a first end portion connected with said input member and a sec- 0nd end portion connected directly to said second head end portion of said shaft and which twists about its longitudinal axis upon rotation of said input member, said pair of resiliently twistable blades being of equal length and wherein said shaft has a slot therein for receiving one end portion of said blades, the other end portion of said blades being located in a slot in said input shaft, said input shaft further having a locating hole for receiving axially projecting tongues formed on said blades, said blades having a body with corners and protuberances located adjacent the corners and which engage surfaces defining said slots to prevent engagement of the body of the blades with the surface of the slots as the blades are twisted. 

1. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing having first and second outlet ports, gerotor gear means connected with said housing and operable in one direction to provide a metered flow of fluid to said first outlet port and operable in another direction to provide a metered flow of fluid to said second outlet port, commutator valve means associated with said gerotor gear means for directing fluid to and from said gerotor gear means, directional control valve means for porting fluid to said commutator valve means and for porting fluid received from said commutator valve means to one of said outlets, said directional control valve means including a valve member movable in a first direction from an initial position to a first actuated position to port a flow of fluid to said commutator valve means and to port fluid from said commutator valve means to said first outlet and movable in a second direction from the initial position to a second actuated position to port a flow of fluid to said commutator valve means and to port fluit from said commutator valve means to said second outlet, an input member operatively connected with said valve member, said input member being rotatable in a first direction to effect movement of said valve member from said initial position to said first actuated position and being rotatable in a second direction to effect movement of said valve member from said initial position to said second actuating position, resiliently twistable blade means operatively connected with said input member and said directional central valve means for storing energy to effect movement of said valve member from said actuated positions back to said initial position, means for enabling twisting of said blade means about the central axis thereof upon rotation of said input member to store energy to effect subsequent movement of said valve member from one of said actuated positions to said initial position, and said blade means being located in a fluid flow path between said commutator valve means and said directional control valve means.
 2. An apparatus as set forth in claim 1 wherein said gerotor gear meanS includes an internally toothed stator member and an externally toothed rotor member circumscribed by said stator member, said rotor member having one less tooth than said stator member and being rotatable about its own central axis and orbital about the central axis of said stator member during operation of gerotor gear means.
 3. An apparatus as set forth in claim 1 wherein said blade means includes a blade member having major sides of a first area and minor sides of a second area which is substantially less than said first area.
 4. An apparatus as set forth in claim 1 wherein said blade means includes a pair of blade members each of which has one end portion connected with said input member and another end portion connected with said gerotor gear.
 5. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing having first and second outlet ports, gerotor gear means connected with said housing and operable in one direction to provide a metered flow of fluid to said first outlet port and operable in another direction to provide a metered flow of fluid to said second outlet port, commutator valve means associated with said gerotor gear means for directing fluid to and from said gerotor gear means, directional control valve means for porting fluid to said commutator valve means and for porting fluid received from said commutator valve means to one of said outlets, said directional valve means including a valve member movable in a first direction from an initial position to a first actuated position to port a flow of fluid to said commutator valve means and to port fluid from said commutator valve means to said first outlet and movable in a second direction from the initial position to a second actuated position to port a flow of fluid to said commutator valve means and to port fluid from said commutator valve means to said second outlet, an input member operatively connected with said valve member, said input member being rotatable in a first direction to effect movement of said valve member from said initial position to said first actuated position and being rotatable in a second direction to effect movement of said valve member from said initial position to said second actuated position, resiliently twistable blade means operatively connected with said input member and said valve means for storing energy to effect movement of said valve member from said actuated positions back to said initial position, and means for enabling twisting of said blade means about the central axis thereof upon rotation of said input member to store energy to effect subsequent movement of said valve member from one of said actuated positions to said initial position, said gerotor gear means including an internally toothed stator and an externally toothed rotor disposed in meshing engagement with said stator, said rotor having one less tooth than said stator and being rotatable about its own central axis and orbital about the central axis of said stator during operation of said gerotor gear means, a wobble shaft having a first head end portion connected with said rotor for rotational and orbital movement therewith and a second head end portion connected with said valve member, said blade means having an end portion connected directly to said second head end portion of said wobble shaft.
 6. An apparatus as set forth in claim 5 wherein said second head end portion of said wobble shaft includes surface means for defining a slot in the second head end portion of said wobble shaft, said end portion of said blade means being disposed in said slot.
 7. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing, gerotor gear means connected with said housing and operable in one direction to provide a metered flow of fluid to a first port and operable in another direction to provide a metered flow of fluid to a second port, valve means for porting fluid to said gerotor gear means, said valve means including a valve member movable in a first direction from an initial position to a first actuated position to port a flow of fluid to said gerotor gear means during operation of said gerotor gear means in the one direction and movable in a second direction from the initial position to a second actuated position to port a flow of fluid to said gerotor gear means during operation of said gerotor gear means in the other direction, an input member connected with said valve member, said input member being rotatable in a first direction in response to one input force to effect movement of said valve member from said initial position to said first actuated position and being rotatable in a second direction in response to another input force to effect movement of said valve member from said initial position to said second actuated position, resiliently twistable blade means connected with said input member and said gerotor gear means for storing energy to effect movement of said valve member from one of said actuated positions to said initial position upon interruption of the input force on the input member and means for effecting twisting said blade means about its central axis upon rotation of said input member to store energy to effect subsequent movement of said valve member from one of said actuated positions to said initial position, said blade means including a pair of blade members each of which has one end portion connected with said input member and another end portion connected with said gerotor gear means, each of said pair of blade members having a convexly curved major side and a concavely curved major side, said pair of blade members being disposed in a side-by-side relationship with said concavely curved major side of one of said blade members facing a curved major side of the other of said blade members.
 8. An apparatus as set forth in claim 7 further including first surface means fixedly connected with said input member for engaging said convexly curved major sides of each of said blade members and pressing said blade members toward each other to provide a tight connection between said blade members and said input member, and second surface means connected with said valve member for engaging said convexly curved major sides of each of said blade members and pressing said blade members toward each other to provide a tight connection between said blade member and said valve member.
 9. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing having an inlet port and a pair of outlet ports, metering means located in said housing and operable to provide a metered flow of fluid, said metering means including an internally toothed member and an externally toothed member disposed in meshing engagement and supported for relative orbital and rotational movements, valve means located in said housing and operable from an initial condition to an actuated condition to port fluid to said metering means and to port fluid from said metering means to a selected one of said outlet ports, a shaft having a first head end portion connected with said externally toothed member for movement therewith and a second head end portion connected with said valve means, a rotatable input member, and means for enabling operation of said valve means from the initial condition to an actuated condition in response to rotation of said input member and for storing energy to effect operation of said valve means from an actuated condition to said initial condition, and means including a pair of resiliently twistable blade having a first end portion connected with said input member and a second end portion connected directly to said second head end portion of said shaft and which twists about its longitudinal axis upon rotation of said input member, said pair of resiliently twistable blades being of equal length and wherein said shaft has a slot therein for receiving one end portion of said blades, the other end portion of said blades being located in a slot in said input shaft, said input shaft further Having a locating hole for receiving axially projecting tongues formed on said blades, each of said pair of blade members having a convexly curved major side and a concavely curved major side, said pair of blade members being disposed in a side-by-side relationship with said cancavely curved major side of one of said blade members facing a concavely curved major side of the other of said blade members.
 10. An apparatus for use in controlling a flow of fluid, said apparatus comprising a housing having an inlet port and a pair of outlet ports, metering means located in said housing and operable to provide a metered flow of fluid, said metering means including an internally toothed member and an externally toothed member disposed in meshing engagement and supported for relative orbital and rotational movements, valve means located in said housing and operable from an initial condition to an actuated condition to port fluid to said metering means and to port fluid from said metering means to a selected one of said outlet ports, a shaft having a first head end portion connected with said externally toothed member for movement therwith and a second head end portion connected with said valve means, a rotatable input member, and means for enabling operation of said valve means from the initial condition to an actuated condition in response to rotation of said input member and for storing energy to effect operation of said valve means from an actuated condition to said initial condition, said means including a pair of resiliently twistable blade having a first end portion connected with said input member and a second end portion connected directly to said second head end portion of said shaft and which twists about its longitudinal axis upon rotation of said input member, said pair of resiliently twistable blades being of equal length and wherein said shaft has a slot therein for receiving one end portion of said blades, the other end portion of said blades being located in a slot in said input shaft, said input shaft further having a locating hole for receiving axially projecting tongues formed on said blades, said blades having a body with corners and protuberances located adjacent the corners and which engage surfaces defining said slots to prevent engagement of the body of the blades with the surface of the slots as the blades are twisted. 